The official said all 24 crew members -- mostly Russian -- who are still on board the ship are safe. They were not harmed by the hijackers, he said.
The company will also have to evaluate the state of the ship, the official said, after the pirates damaged some electronics and communications equipment.
The Isle of Man-flagged vessel was hijacked off the coast of the Togolese capital Lome, where it was anchored.
Once on board, the pirates exchanged gunfire with a Togo naval ship that responded to a distress call, before they disappeared off the coast of neighboring Benin.
This is the second such attack in less than two weeks in the Gulf of Guinea, off the west coast of Africa.